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geotiff

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GeoTIFF image decoding in JavaScript

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/** @module geotiffimage */ import { getFloat16 } from '@petamoriken/float16'; // @ts-expect-error import getAttribute from 'xml-utils/get-attribute'; // eslint-disable-line import/extensions // @ts-expect-error import findTagsByName from 'xml-utils/find-tags-by-name'; // eslint-disable-line import/extensions import { photometricInterpretations, ExtraSamplesValues } from './globals.js'; import { fromWhiteIsZero, fromBlackIsZero, fromPalette, fromCMYK, fromYCbCr, fromCIELab } from './rgb.js'; import { getDecoder, getDecoderParameters } from './compression/index.js'; import { resample, resampleInterleaved } from './resample.js'; /** @import {DecoderWorker, TypedArray} from "./geotiff.js" */ /** @import {ReadRasterResult} from "./geotiff.js" */ /** @import {ReadRastersOptions} from "./geotiff.js" */ /** @import {ReadRGBOptions} from "./geotiff.js" */ /** * @param {Array<number>|TypedArray} array * @param {number} start * @param {number} end * @returns {number} */ function sum(array, start, end) { let s = 0; for (let i = start; i < end; ++i) { s += array[i]; } return s; } /** * @param {1|2|3} format * @param {number} bitsPerSample * @param {number|ArrayBufferLike} sizeOrData * @returns {TypedArray} */ function arrayForType(format, bitsPerSample, sizeOrData) { let TypedArrayConstructor; switch (format) { case 1: // unsigned integer data if (bitsPerSample <= 8) { TypedArrayConstructor = Uint8Array; } else if (bitsPerSample <= 16) { TypedArrayConstructor = Uint16Array; } else if (bitsPerSample <= 32) { TypedArrayConstructor = Uint32Array; } break; case 2: // twos complement signed integer data if (bitsPerSample === 8) { TypedArrayConstructor = Int8Array; } else if (bitsPerSample === 16) { TypedArrayConstructor = Int16Array; } else if (bitsPerSample === 32) { TypedArrayConstructor = Int32Array; } break; case 3: // floating point data switch (bitsPerSample) { case 16: case 32: TypedArrayConstructor = Float32Array; break; case 64: TypedArrayConstructor = Float64Array; break; default: break; } break; default: break; } if (TypedArrayConstructor) { if (typeof sizeOrData === 'number') { return new TypedArrayConstructor(sizeOrData); } else if (sizeOrData instanceof ArrayBuffer) { return new TypedArrayConstructor(sizeOrData); } } throw Error('Unsupported data format/bitsPerSample'); } /** * @param {1|2|3} format * @param {number} bitsPerSample * @returns {boolean} */ function needsNormalization(format, bitsPerSample) { if ((format === 1 || format === 2) && bitsPerSample <= 32 && bitsPerSample % 8 === 0) { return false; } else if (format === 3 && (bitsPerSample === 16 || bitsPerSample === 32 || bitsPerSample === 64)) { return false; } return true; } /** * @param {ArrayBufferLike} inBuffer * @param {1|2|3} format * @param {1|2} planarConfiguration * @param {number} samplesPerPixel * @param {number} bitsPerSample * @param {number} tileWidth * @param {number} tileHeight * @returns {ArrayBufferLike} */ function normalizeArray(inBuffer, format, planarConfiguration, samplesPerPixel, bitsPerSample, tileWidth, tileHeight) { // const inByteArray = new Uint8Array(inBuffer); const view = new DataView(inBuffer); const outSize = planarConfiguration === 2 ? tileHeight * tileWidth : tileHeight * tileWidth * samplesPerPixel; const samplesToTransfer = planarConfiguration === 2 ? 1 : samplesPerPixel; const outArray = arrayForType(format, bitsPerSample, outSize); // let pixel = 0; const bitMask = parseInt('1'.repeat(bitsPerSample), 2); if (format === 1) { // unsigned integer // translation of https://github.com/OSGeo/gdal/blob/master/gdal/frmts/gtiff/geotiff.cpp#L7337 let pixelBitSkip; // let sampleBitOffset = 0; if (planarConfiguration === 1) { pixelBitSkip = samplesPerPixel * bitsPerSample; // sampleBitOffset = (samplesPerPixel - 1) * bitsPerSample; } else { pixelBitSkip = bitsPerSample; } // Bits per line rounds up to next byte boundary. let bitsPerLine = tileWidth * pixelBitSkip; if ((bitsPerLine & 7) !== 0) { bitsPerLine = (bitsPerLine + 7) & (~7); } for (let y = 0; y < tileHeight; ++y) { const lineBitOffset = y * bitsPerLine; for (let x = 0; x < tileWidth; ++x) { const pixelBitOffset = lineBitOffset + (x * samplesToTransfer * bitsPerSample); for (let i = 0; i < samplesToTransfer; ++i) { const bitOffset = pixelBitOffset + (i * bitsPerSample); const outIndex = (((y * tileWidth) + x) * samplesToTransfer) + i; const byteOffset = Math.floor(bitOffset / 8); const innerBitOffset = bitOffset % 8; if (innerBitOffset + bitsPerSample <= 8) { outArray[outIndex] = (view.getUint8(byteOffset) >> (8 - bitsPerSample) - innerBitOffset) & bitMask; } else if (innerBitOffset + bitsPerSample <= 16) { outArray[outIndex] = (view.getUint16(byteOffset) >> (16 - bitsPerSample) - innerBitOffset) & bitMask; } else if (innerBitOffset + bitsPerSample <= 24) { const raw = (view.getUint16(byteOffset) << 8) | (view.getUint8(byteOffset + 2)); outArray[outIndex] = (raw >> (24 - bitsPerSample) - innerBitOffset) & bitMask; } else { outArray[outIndex] = (view.getUint32(byteOffset) >> (32 - bitsPerSample) - innerBitOffset) & bitMask; } // let outWord = 0; // for (let bit = 0; bit < bitsPerSample; ++bit) { // if (inByteArray[bitOffset >> 3] // & (0x80 >> (bitOffset & 7))) { // outWord |= (1 << (bitsPerSample - 1 - bit)); // } // ++bitOffset; // } // outArray[outIndex] = outWord; // outArray[pixel] = outWord; // pixel += 1; } // bitOffset = bitOffset + pixelBitSkip - bitsPerSample; } } } else if (format === 3) { // floating point // Float16 is handled elsewhere // normalize 16/24 bit floats to 32 bit floats in the array // console.time(); // if (bitsPerSample === 16) { // for (let byte = 0, outIndex = 0; byte < inBuffer.byteLength; byte += 2, ++outIndex) { // outArray[outIndex] = getFloat16(view, byte); // } // } // console.timeEnd() } return outArray.buffer; } /** * GeoTIFF sub-file image. */ class GeoTIFFImage { /** * @constructor * @param {import("./imagefiledirectory.js").ImageFileDirectory} fileDirectory The parsed file directory * @param {Boolean} littleEndian Whether the file is encoded in little or big endian * @param {Boolean} cache Whether or not decoded tiles shall be cached * @param {import('./source/basesource.js').BaseSource} source The datasource to read from */ constructor(fileDirectory, littleEndian, cache, source) { this.fileDirectory = fileDirectory; this.littleEndian = littleEndian; /** @type {Array<Promise<ArrayBufferLike>>|null} */ this.tiles = cache ? [] : null; this.isTiled = !fileDirectory.hasTag('StripOffsets'); const planarConfiguration = fileDirectory.getValue('PlanarConfiguration') ?? 1; if (planarConfiguration !== 1 && planarConfiguration !== 2) { throw new Error('Invalid planar configuration.'); } /** @type {1 | 2} */ this.planarConfiguration = planarConfiguration; this.source = source; } /** * Returns the associated parsed file directory. * @returns {import("./imagefiledirectory.js").ImageFileDirectory} the parsed file directory */ getFileDirectory() { return this.fileDirectory; } /** * Returns the associated parsed geo keys. * @returns {Partial<Record<import('./globals.js').GeoKeyName, *>>|null} the parsed geo keys */ getGeoKeys() { return this.fileDirectory.parseGeoKeyDirectory(); } /** * Returns the width of the image. * @returns {Number} the width of the image */ getWidth() { return this.fileDirectory.getValue('ImageWidth') || 0; } /** * Returns the height of the image. * @returns {Number} the height of the image */ getHeight() { return this.fileDirectory.getValue('ImageLength') || 0; } /** * Returns the number of samples per pixel. * @returns {number} the number of samples per pixel */ getSamplesPerPixel() { return this.fileDirectory.getValue('SamplesPerPixel') ?? 1; } /** * Returns the width of each tile. * @returns {number} the width of each tile */ getTileWidth() { return this.isTiled ? (this.fileDirectory.getValue('TileWidth') || 0) : this.getWidth(); } /** * Returns the height of each tile. * @returns {number} the height of each tile */ getTileHeight() { if (this.isTiled) { return this.fileDirectory.getValue('TileLength') || 0; } const rowsPerStrip = this.fileDirectory.hasTag('RowsPerStrip') && this.fileDirectory.getValue('RowsPerStrip'); if (rowsPerStrip) { return Math.min(rowsPerStrip, this.getHeight()); } return this.getHeight(); } getBlockWidth() { return this.getTileWidth(); } /** * @param {number} y * @returns {number} */ getBlockHeight(y) { if (this.isTiled || (y + 1) * this.getTileHeight() <= this.getHeight()) { return this.getTileHeight(); } else { return this.getHeight() - (y * this.getTileHeight()); } } /** * Calculates the number of bytes for each pixel across all samples. Only full * bytes are supported, an exception is thrown when this is not the case. * @returns {Number} the bytes per pixel */ getBytesPerPixel() { let bytes = 0; // this is a short list, so we assume this is already loaded const bitsPerSample = this.fileDirectory.getValue('BitsPerSample') || []; for (let i = 0; i < bitsPerSample.length; ++i) { bytes += this.getSampleByteSize(i); } return bytes; } /** * @param {number} i * @returns {number} */ getSampleByteSize(i) { const bitsPerSample = this.fileDirectory.getValue('BitsPerSample') || []; if (i >= bitsPerSample.length) { throw new RangeError(`Sample index ${i} is out of range.`); } return Math.ceil(bitsPerSample[i] / 8); } /** * @param {number} sampleIndex * @returns {(this: DataView, byteOffset: number, littleEndian: boolean) => number} */ getReaderForSample(sampleIndex) { const sampleFormat = this.fileDirectory.getValue('SampleFormat'); const format = sampleFormat ? sampleFormat[sampleIndex] : 1; const bitsPerSample = (this.fileDirectory.getValue('BitsPerSample') || [])[sampleIndex]; switch (format) { case 1: // unsigned integer data if (bitsPerSample <= 8) { return DataView.prototype.getUint8; } else if (bitsPerSample <= 16) { return DataView.prototype.getUint16; } else if (bitsPerSample <= 32) { return DataView.prototype.getUint32; } break; case 2: // twos complement signed integer data if (bitsPerSample <= 8) { return DataView.prototype.getInt8; } else if (bitsPerSample <= 16) { return DataView.prototype.getInt16; } else if (bitsPerSample <= 32) { return DataView.prototype.getInt32; } break; case 3: switch (bitsPerSample) { case 16: return function (offset, littleEndian) { return getFloat16(this, offset, littleEndian); }; case 32: return DataView.prototype.getFloat32; case 64: return DataView.prototype.getFloat64; default: break; } break; default: break; } throw Error('Unsupported data format/bitsPerSample'); } getSampleFormat(sampleIndex = 0) { const sampleFormat = this.fileDirectory.getValue('SampleFormat'); return sampleFormat ? sampleFormat[sampleIndex] : 1; } getBitsPerSample(sampleIndex = 0) { const bitsPerSample = this.fileDirectory.getValue('BitsPerSample'); return bitsPerSample ? bitsPerSample[sampleIndex] : 0; } /** * @param {number} sampleIndex * @param {number|ArrayBufferLike} sizeOrData * @returns {TypedArray} */ getArrayForSample(sampleIndex, sizeOrData) { const format = /** @type {1|2|3} */ (this.getSampleFormat(sampleIndex)); const bitsPerSample = this.getBitsPerSample(sampleIndex); return arrayForType(format, bitsPerSample, sizeOrData); } /** * Returns the decoded strip or tile. * @param {Number} x the strip or tile x-offset * @param {Number} y the tile y-offset (0 for stripped images) * @param {Number} sample the sample to get for separated samples * @param {DecoderWorker|import("./geotiff.js").BaseDecoder} poolOrDecoder the decoder or decoder pool * @param {AbortSignal} [signal] An AbortSignal that may be signalled if the request is * to be aborted * @returns {Promise.<{x: number, y: number, sample: number, data: ArrayBufferLike}>} the decoded strip or tile */ async getTileOrStrip(x, y, sample, poolOrDecoder, signal) { const numTilesPerRow = Math.ceil(this.getWidth() / this.getTileWidth()); const numTilesPerCol = Math.ceil(this.getHeight() / this.getTileHeight()); let index; const { tiles } = this; if (this.planarConfiguration === 1) { index = (y * numTilesPerRow) + x; } else if (this.planarConfiguration === 2) { index = (sample * numTilesPerRow * numTilesPerCol) + (y * numTilesPerRow) + x; } if (index === undefined) { throw new Error('Could not determine tile or strip index.'); } let offset; let byteCount; if (this.isTiled) { offset = Number(await this.fileDirectory.loadValueIndexed('TileOffsets', index)); byteCount = Number(await this.fileDirectory.loadValueIndexed('TileByteCounts', index)); } else { offset = Number(await this.fileDirectory.loadValueIndexed('StripOffsets', index)); byteCount = Number(await this.fileDirectory.loadValueIndexed('StripByteCounts', index)); } if (byteCount === 0) { const nPixels = this.getBlockHeight(y) * this.getTileWidth(); const bytesPerPixel = (this.planarConfiguration === 2) ? this.getSampleByteSize(sample) : this.getBytesPerPixel(); const data = new ArrayBuffer(nPixels * bytesPerPixel); const view = this.getArrayForSample(sample, data); view.fill(this.getGDALNoData() || 0); return { x, y, sample, data }; } const slice = (await this.source.fetch([{ offset, length: byteCount }], signal))[0]; let request; if (tiles === null || !tiles[index]) { // resolve each request by potentially applying array normalization request = (async () => { let data = await poolOrDecoder.decode(slice); const sampleFormat = /** @type {1|2|3} */ (this.getSampleFormat()); const bitsPerSample = this.getBitsPerSample(); if (needsNormalization(sampleFormat, bitsPerSample)) { data = normalizeArray(data, sampleFormat, this.planarConfiguration, this.getSamplesPerPixel(), bitsPerSample, this.getTileWidth(), this.getBlockHeight(y)); } return data; })(); // set the cache if (tiles !== null) { tiles[index] = request; } } else { // get from the cache request = tiles[index]; } // cache the tile request return { x, y, sample, data: await request }; } /** * Internal read function. * @private * @param {Array<number>} imageWindow The image window in pixel coordinates * @param {Array<number>} samples The selected samples (0-based indices) * @param {TypedArray|TypedArray[]} valueArrays The array(s) to write into * @param {boolean|undefined} interleave Whether or not to write in an interleaved manner * @param {DecoderWorker|import("./geotiff.js").BaseDecoder} poolOrDecoder the decoder or decoder pool * @param {number} [width] the width of window to be read into * @param {number} [height] the height of window to be read into * @param {string} [resampleMethod] the resampling method to be used when interpolating * @param {AbortSignal} [signal] An AbortSignal that may be signalled if the request is * to be aborted * @returns {Promise<ReadRasterResult>} */ async _readRaster(imageWindow, samples, valueArrays, interleave, poolOrDecoder, width, height, resampleMethod, signal) { const tileWidth = this.getTileWidth(); const tileHeight = this.getTileHeight(); const imageWidth = this.getWidth(); const imageHeight = this.getHeight(); const minXTile = Math.max(Math.floor(imageWindow[0] / tileWidth), 0); const maxXTile = Math.min(Math.ceil(imageWindow[2] / tileWidth), Math.ceil(imageWidth / tileWidth)); const minYTile = Math.max(Math.floor(imageWindow[1] / tileHeight), 0); const maxYTile = Math.min(Math.ceil(imageWindow[3] / tileHeight), Math.ceil(imageHeight / tileHeight)); const windowWidth = imageWindow[2] - imageWindow[0]; let bytesPerPixel = this.getBytesPerPixel(); /** @type {Array<number>} */ const srcSampleOffsets = []; /** @type {Array<(this: DataView, byteOffset: number, littleEndian: boolean) => number>} */ const sampleReaders = []; for (let i = 0; i < samples.length; ++i) { if (this.planarConfiguration === 1) { const bitsPerSample = await this.fileDirectory.loadValue('BitsPerSample'); if (typeof bitsPerSample !== 'object') { throw new Error('Expected BitsPerSample to be an array or typed array.'); } srcSampleOffsets.push(sum(bitsPerSample, 0, samples[i]) / 8); } else { srcSampleOffsets.push(0); } sampleReaders.push(this.getReaderForSample(samples[i])); } const promises = []; const { littleEndian } = this; for (let yTile = minYTile; yTile < maxYTile; ++yTile) { for (let xTile = minXTile; xTile < maxXTile; ++xTile) { let getPromise; if (this.planarConfiguration === 1) { getPromise = this.getTileOrStrip(xTile, yTile, 0, poolOrDecoder, signal); } for (let sampleIndex = 0; sampleIndex < samples.length; ++sampleIndex) { const si = sampleIndex; const sample = samples[sampleIndex]; if (this.planarConfiguration === 2) { bytesPerPixel = this.getSampleByteSize(sample); getPromise = this.getTileOrStrip(xTile, yTile, sample, poolOrDecoder, signal); } if (!getPromise) { throw new Error('Could not get tile or strip data.'); } const promise = getPromise.then((tile) => { const buffer = tile.data; const dataView = new DataView(buffer); const blockHeight = this.getBlockHeight(tile.y); const firstLine = tile.y * tileHeight; const firstCol = tile.x * tileWidth; const lastLine = firstLine + blockHeight; const lastCol = (tile.x + 1) * tileWidth; const reader = sampleReaders[si]; const ymax = Math.min(blockHeight, blockHeight - (lastLine - imageWindow[3]), imageHeight - firstLine); const xmax = Math.min(tileWidth, tileWidth - (lastCol - imageWindow[2]), imageWidth - firstCol); for (let y = Math.max(0, imageWindow[1] - firstLine); y < ymax; ++y) { for (let x = Math.max(0, imageWindow[0] - firstCol); x < xmax; ++x) { const pixelOffset = ((y * tileWidth) + x) * bytesPerPixel; const value = reader.call(dataView, pixelOffset + srcSampleOffsets[si], littleEndian); let windowCoordinate; if (interleave) { windowCoordinate = ((y + firstLine - imageWindow[1]) * windowWidth * samples.length) + ((x + firstCol - imageWindow[0]) * samples.length) + si; valueArrays[windowCoordinate] = value; } else { windowCoordinate = ((y + firstLine - imageWindow[1]) * windowWidth) + x + firstCol - imageWindow[0]; /** @type {TypedArray} */ (valueArrays[si])[windowCoordinate] = value; } } } }); promises.push(promise); } } } await Promise.all(promises); if ((width && (imageWindow[2] - imageWindow[0]) !== width) || (height && (imageWindow[3] - imageWindow[1]) !== height)) { let resampled; if (interleave) { resampled = resampleInterleaved( /** @type {TypedArray} */ (valueArrays), imageWindow[2] - imageWindow[0], imageWindow[3] - imageWindow[1], /** @type {number} */ (width), /** @type {number} */ (height), samples.length, resampleMethod); } else { resampled = resample( /** @type {TypedArray[]} */ (valueArrays), imageWindow[2] - imageWindow[0], imageWindow[3] - imageWindow[1], /** @type {number} */ (width), /** @type {number} */ (height), resampleMethod); } const resampledWithDimensions = /** @type {ReadRasterResult} */ (resampled); resampledWithDimensions.width = width ?? imageWindow[2] - imageWindow[0]; resampledWithDimensions.height = height ?? imageWindow[3] - imageWindow[1]; return resampledWithDimensions; } const valueArraysWithDimensions = /** @type {ReadRasterResult} */ (valueArrays); valueArraysWithDimensions.width = width || imageWindow[2] - imageWindow[0]; valueArraysWithDimensions.height = height || imageWindow[3] - imageWindow[1]; return valueArraysWithDimensions; } /** * @overload * @param {ReadRastersOptions & {interleave: true}} options optional parameters * @returns {Promise<import("./geotiff.js").TypedArrayWithDimensions>} the decoded arrays as a promise */ /** * @overload * @param {ReadRastersOptions & {interleave: false}} options optional parameters * @returns {Promise<import("./geotiff.js").TypedArrayArrayWithDimensions>} the decoded arrays as a promise */ /** * @overload * @param {ReadRastersOptions & {interleave: boolean}} options optional parameters * @returns {Promise<ReadRasterResult>} the decoded arrays as a promise */ /** * @overload * @param {ReadRastersOptions} [options={}] optional parameters * @returns {Promise<import("./geotiff.js").TypedArrayArrayWithDimensions>} the decoded arrays as a promise */ /** * Reads raster data from the image. This function reads all selected samples * into separate arrays of the correct type for that sample or into a single * combined array when `interleave` is set. When provided, only a subset * of the raster is read for each sample. * * @param {ReadRastersOptions} [options={}] optional parameters * @returns {Promise<ReadRasterResult>} the decoded arrays as a promise */ async readRasters(options = {}) { const { window: wnd, samples = [], pool = null, width, height, resampleMethod, fillValue, signal, } = options; const interleave = 'interleave' in options && options.interleave; const imageWindow = wnd || [0, 0, this.getWidth(), this.getHeight()]; // check parameters if (imageWindow[0] > imageWindow[2] || imageWindow[1] > imageWindow[3]) { throw new Error('Invalid subsets'); } const imageWindowWidth = imageWindow[2] - imageWindow[0]; const imageWindowHeight = imageWindow[3] - imageWindow[1]; const numPixels = imageWindowWidth * imageWindowHeight; const samplesPerPixel = this.getSamplesPerPixel(); if (!samples || !samples.length) { for (let i = 0; i < samplesPerPixel; ++i) { samples.push(i); } } else { for (let i = 0; i < samples.length; ++i) { if (samples[i] >= samplesPerPixel) { return Promise.reject(new RangeError(`Invalid sample index '${samples[i]}'.`)); } } } /** @type {TypedArray|TypedArray[]} */ let valueArrays; if (interleave) { const { fileDirectory } = this; const sampleFormat = fileDirectory.getValue('SampleFormat'); const format = sampleFormat ? Math.max.apply(null, Array.from(sampleFormat)) : 1; if (format !== 1 && format !== 2 && format !== 3) { throw new Error('Unsupported sample format for interleaved data. Must be 1, 2, or 3.'); } const bitsPerSample_ = fileDirectory.getValue('BitsPerSample'); const bitsPerSample = bitsPerSample_ ? Math.max.apply(null, Array.from(bitsPerSample_)) : 8; valueArrays = arrayForType(format, bitsPerSample, numPixels * samples.length); if (fillValue) { if (Array.isArray(fillValue)) { throw new Error('When reading interleaved data, fillValue must be a single number.'); } valueArrays.fill(fillValue); } } else { valueArrays = []; for (let i = 0; i < samples.length; ++i) { const valueArray = this.getArrayForSample(samples[i], numPixels); if (Array.isArray(fillValue) && i < fillValue.length) { valueArray.fill(fillValue[i]); } else if (fillValue && !Array.isArray(fillValue)) { valueArray.fill(fillValue); } valueArrays.push(valueArray); } } const compression = this.fileDirectory.getValue('Compression') || 1; const decoderParameters = await getDecoderParameters(compression, this.fileDirectory); const poolOrDecoder = pool ? pool.bindParameters(compression, decoderParameters) : await getDecoder(compression, decoderParameters); const result = await this._readRaster(imageWindow, samples, valueArrays, interleave, poolOrDecoder, width, height, resampleMethod, signal); return result; } /** * @overload * @param {ReadRGBOptions & {interleave: true}} options optional parameters * @returns {Promise<import("./geotiff.js").TypedArrayWithDimensions>} the RGB array as a Promise */ /** * @overload * @param {ReadRGBOptions & {interleave: false}} options optional parameters * @returns {Promise<import("./geotiff.js").TypedArrayArrayWithDimensions>} the RGB array as a Promise */ /** * @overload * @param {ReadRGBOptions & {interleave: boolean}} options optional parameters * @returns {Promise<ReadRasterResult>} the RGB array as a Promise */ /** * @overload * @param {ReadRGBOptions} [options={}] optional parameters * @returns {Promise<import("./geotiff.js").TypedArrayArrayWithDimensions>} the RGB array as a Promise */ /** * Reads raster data from the image as RGB. * Colorspaces other than RGB will be transformed to RGB, color maps expanded. * When no other method is applicable, the first sample is used to produce a * grayscale image. * When provided, only a subset of the raster is read for each sample. * * @param {ReadRGBOptions} [options] optional parameters * @returns {Promise<ReadRasterResult>} the RGB array as a Promise */ async readRGB(options = {}) { const { window, pool = null, width, height, resampleMethod, enableAlpha = false, signal } = options; const interleave = ('interleave' in options && options.interleave) ?? false; const imageWindow = window || [0, 0, this.getWidth(), this.getHeight()]; // check parameters if (imageWindow[0] > imageWindow[2] || imageWindow[1] > imageWindow[3]) { throw new Error('Invalid subsets'); } const pi = this.fileDirectory.getValue('PhotometricInterpretation'); if (pi === photometricInterpretations.RGB) { let s = [0, 1, 2]; const extraSamples = this.fileDirectory.getValue('ExtraSamples'); if (extraSamples && extraSamples[0] !== ExtraSamplesValues.Unspecified && enableAlpha) { s = []; const bitsPerSample = this.fileDirectory.getValue('BitsPerSample') || []; for (let i = 0; i < bitsPerSample.length; i += 1) { s.push(i); } } return this.readRasters({ window, interleave, samples: s, pool, width, height, resampleMethod, signal, }); } let samples; switch (pi) { case photometricInterpretations.WhiteIsZero: case photometricInterpretations.BlackIsZero: case photometricInterpretations.Palette: samples = [0]; break; case photometricInterpretations.CMYK: samples = [0, 1, 2, 3]; break; case photometricInterpretations.YCbCr: case photometricInterpretations.CIELab: samples = [0, 1, 2]; break; default: throw new Error('Invalid or unsupported photometric interpretation.'); } const subOptions = { window: imageWindow, /** @type {true} */ interleave: true, samples, pool, width, height, resampleMethod, signal, }; const { fileDirectory } = this; const raster = await this.readRasters(subOptions); const max = 2 ** this.getBitsPerSample(0); let data; switch (pi) { case photometricInterpretations.WhiteIsZero: data = fromWhiteIsZero(raster, max); break; case photometricInterpretations.BlackIsZero: data = fromBlackIsZero(raster, max); break; case photometricInterpretations.Palette: data = fromPalette(raster, /** @type {Uint16Array} */ (await fileDirectory.loadValue('ColorMap'))); break; case photometricInterpretations.CMYK: data = fromCMYK(raster); break; case photometricInterpretations.YCbCr: data = fromYCbCr(raster); break; case photometricInterpretations.CIELab: data = fromCIELab(raster); break; default: throw new Error('Unsupported photometric interpretation.'); } // if non-interleaved data is requested, we must split the channels // into their respective arrays if (!interleave) { const red = new Uint8Array(data.length / 3); const green = new Uint8Array(data.length / 3); const blue = new Uint8Array(data.length / 3); for (let i = 0, j = 0; i < data.length; i += 3, ++j) { red[j] = data[i]; green[j] = data[i + 1]; blue[j] = data[i + 2]; } data = [red, green, blue]; } const dataWithDimensions = /** @type {import("./geotiff.js").ReadRasterResult} */ (data); dataWithDimensions.width = raster.width; dataWithDimensions.height = raster.height; return dataWithDimensions; } /** * Returns an array of tiepoints. * @returns {Promise<Array<{i: number, j: number, k: number, x: number, y: number, z: number}>>} the tiepoints */ async getTiePoints() { if (!this.fileDirectory.hasTag('ModelTiepoint')) { return []; } const modelTiePoint = await this.fileDirectory.loadValue('ModelTiepoint'); if (typeof modelTiePoint !== 'object') { throw new Error('Expected ModelTiepoint to be an array or typed array.'); } const tiePoints = []; for (let i = 0; i < modelTiePoint.length; i += 6) { tiePoints.push({ i: modelTiePoint[i], j: modelTiePoint[i + 1], k: modelTiePoint[i + 2], x: modelTiePoint[i + 3], y: modelTiePoint[i + 4], z: modelTiePoint[i + 5], }); } return tiePoints; } /** * Returns the parsed GDAL metadata items. * * If sample is passed to null, dataset-level metadata will be returned. * Otherwise only metadata specific to the provided sample will be returned. * * @param {number|null} [sample=null] The sample index. * @returns {Promise<Record<string, unknown>|null>} The GDAL metadata items */ async getGDALMetadata(sample = null) { /** @type {Record<string, unknown>} */ const metadata = {}; if (!this.fileDirectory.hasTag('GDAL_METADATA')) { return null; } const string = await this.fileDirectory.loadValue('GDAL_METADATA'); /** @type {Array<{inner: unknown}>} */ let items = findTagsByName(string, 'Item'); if (sample === null) { items = items.filter((item) => getAttribute(item, 'sample') === undefined); } else { items = items.filter((item) => Number(getAttribute(item, 'sample')) === sample); } for (let i = 0; i < items.length; ++i) { const item = items[i]; metadata[getAttribute(item, 'name')] = item.inner; } return metadata; } /** * Returns the GDAL nodata value * @returns {number|null} */ getGDALNoData() { const string = this.fileDirectory.hasTag('GDAL_NODATA') && this.fileDirectory.getValue('GDAL_NODATA'); if (!string) { return null; } return Number(string.substring(0, string.length - 1)); } /** * Returns the image origin as a XYZ-vector. When the image has no affine * transformation, then an exception is thrown. * @returns {Array<number>} The origin as a vector */ getOrigin() { const tiePoints = this.fileDirectory.getValue('ModelTiepoint'); const modelTransformation = this.fileDirectory.getValue('ModelTransformation'); if (tiePoints && tiePoints.length === 6) { return [ tiePoints[3], tiePoints[4], tiePoints[5], ]; } if (modelTransformation) { return [ modelTransformation[3], modelTransformation[7], modelTransformation[11], ]; } throw new Error('The image does not have an affine transformation.'); } /** * Returns the image resolution as a XYZ-vector. When the image has no affine * transformation, then an exception is thrown. * @param {GeoTIFFImage|null} [referenceImage=null] A reference image to calculate the resolution from * in cases when the current image does not have the * required tags on its own. * @returns {Array<number>} The resolution as a vector */ getResolution(referenceImage = null) { const modelPixelScale = this.fileDirectory.getValue('ModelPixelScale'); const modelTransformation = this.fileDirectory.getValue('ModelTransformation'); if (modelPixelScale) { return [ modelPixelScale[0], -modelPixelScale[1], modelPixelScale[2], ]; } if (modelTransformation) { if (modelTransformation[1] === 0 && modelTransformation[4] === 0) { return [ modelTransformation[0], -modelTransformation[5], modelTransformation[10], ]; } return [ Math.sqrt((modelTransformation[0] * modelTransformation[0]) + (modelTransformation[4] * modelTransformation[4])), -Math.sqrt((modelTransformation[1] * modelTransformation[1]) + (modelTransformation[5] * modelTransformation[5])), modelTransformation[10] ]; } if (referenceImage) { const [refResX, refResY, refResZ] = referenceImage.getResolution(); return [ refResX * referenceImage.getWidth() / this.getWidth(), refResY * referenceImage.getHeight() / this.getHeight(), refResZ * referenceImage.getWidth() / this.getWidth(), ]; } throw new Error('The image does not have an affine transformation.'); } /** * Returns whether or not the pixels of the image depict an area (or point). * @returns {Boolean} Whether the pixels are a point */ pixelIsArea() { return this.getGeoKeys()?.GTRasterTypeGeoKey === 1; } /** * Returns the image bounding box as an array of 4 values: min-x, min-y, * max-x and max-y. When the image has no affine transformation, then an * exception is thrown. * @param {boolean} [tilegrid=false] If true return extent for a tilegrid * without adjustment for ModelTransformation. * @returns {Array<number>} The bounding box */ getBoundingBox(tilegrid = false) { const height = this.getHeight(); const width = this.getWidth(); const modelTransformation = this.fileDirectory.getValue('ModelTransformation'); if (modelTransformation && !tilegrid) { const [a, b, , d, e, f, , h] = modelTransformation; const corners = [ [0, 0], [0, height], [width, 0], [width, height], ]; const projected = corners.map(([I, J]) => [ d + (a * I) + (b * J), h + (e * I) + (f * J), ]); const xs = projected.map((pt) => pt[0]); const ys = projected.map((pt) => pt[1]); return [ Math.min(...xs), Math.min(...ys), Math.max(...xs), Math.max(...ys), ]; } else { const origin = this.getOrigin(); const resolution = this.getResolution(); const x1 = origin[0]; const y1 = origin[1]; const x2 = x1 + (resolution[0] * width); const y2 = y1 + (resolution[1] * height); return [ Math.min(x1, x2), Math.min(y1, y2), Math.max(x1, x2), Math.max(y1, y2), ]; } } } export default GeoTIFFImage; //# sourceMappingURL=geotiffimage.js.map